Gas turbine engines employ turbine rotors that have a rotor body as well as a plurality of rotor blades that rotate therewith. The rotor blades may be an integral part of the rotor body or they may be separately anchored by a blade root that is positioned in one or a plurality of axially extending grooves of the rotor body. Rotors that have blades that are integral to the rotor body have certain draw backs in view of their unitary design. As such, some aerospace applications have preferred turbine rotors that have rotor blades that are individually anchored to the rotor body by employing axially extending grooves in the rotor body that are operable to receive the blade roots of the rotor blade. Retaining members known as cover plates have been employed to secure the rotor blades axially relative to the rotor body. However, a challenge with such designs is the ease of installing and then maintaining the rotor blades after they have been in service.
Prior methods for retaining a gas turbine blade relative to the rotor or disc body utilize segmented cover plates that require slots to be cut into a groove of the rotor body to allow the cover plates to slide into place, or the blades must be staggered during assembly to create clearance. Slots in the rotor body groove can create high stress areas and my not be a helpful feature. Retention methods utilizing locking wires below the segmented cover plates require machined segmented cover plates which are heavier and more expensive than conventional formed sheet metal segmented cover plates.
Segmented cover plates that are held in place by grooves in the bottom of the blade platforms use a locking wire which interfaces with a groove in the radially inward edge of the cover plates and a groove in the disc. This method requires machined segmented cover plates in order to create the groove for the locking wire. It would be helpful to provide an improved segment cover plate that is formed from sheet metal which is inexpensive and lighter than machined cover plates. A new method of installing the segmented cover plate for retaining a rotor blade axially relative to a rotor body would also be helpful.